Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.

Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.Nghiên cứu chế tạo và đặc trưng tính chất của vật liệu nanocompozit Poly(methyl methacrylat)/zirconia (PMMA/ZrO2) lai ghép hữu cơ ứng dụng làm vật liệu in 3D dạng sợi.

DECLARATION OF AUTHORSHIP I, Nguyen Thi Dieu Linh, hereby declare that the thesis entitled: “Fabrication and characterization of PMMA/ZrO2 hybrid nanocomposites towards the application in 3D printing filaments materials” were carried out by myself under the guidance and supervision of Dr Do Quang Tham and Assoc Prof Dr Nguyen Vu Giang I confirm that: All the results are based on data that I have studied by myself and that are true and have not transgressed research ethics Simultaneously, the data, figures, and results have never been published in any other thesis or diploma Ha Noi, September, 2022 Master student Nguyen Thi Dieu Linh ACKNOWLEDGMENT First of all, I would like to express my gratitude to Dr Do Quang Tham and Assoc Prof Dr Nguyen Vu Giang for their providing guidance, comments and advising me throughout this thesis Without their motivation and instructions, the study would have been impossible to be done effectively The master's dissertation was carried out at the Department of PhysicoChemistry of Non-Metallic Materials, Institute for Tropical Technology, Vietnam Academy of Science and technology I would like to thank all scientists in the Department of Physico-Chemistry of Non-Metallic Materials, Institute for Tropical Technology for their help during I carried out my experiments for the thesis I am also thankful to the lecturers at the Graduate University of Science and Technology for providing me the knowledge and tools that I need throughout my studies and for writing my dissertation And my biggest thanks to my family for all the trust, sympathy, and support for me I could not forget to say a special thank you to my friends, and all the members of the CHE 2020B class, without their help this dissertation would have not been done i CONTENTS CONTENTS i ABBREVIATIONS iii LIST OF FIGURES iv LIST OF TABLES v INTRODUCTION Chapter 1: OVERVIEW 1.1 Three-dimensional (3D) printing technology and 3D printing materials 1.2 Introduction to polymer nanocomposite materials 1.2.1 Definition of polymer nanocomposites, hybrid nanocomposites 1.2.2 Synthesis of polymer nanocomposites 1.3 Poly methyl methacylate (PMMA) 1.3.1 Structure and general properties 1.3.2 Synthesis of PMMA 1.3.3 Advantages and disadvantages of PMMA 12 1.3.4 Applications 13 1.4 Zirconia (ZrO2) 14 1.4.1 Structure and general properties 14 1.4.2 Zirconia fabrication 16 1.4.3 Application 16 1.5 The research status on 3D filaments from PMMA and its composites 17 Chapter 2: EXPERIMENTAL 22 2.1 Materials 22 2.2 Sample preparation 22 2.2.1 Surface modification of ZrO2 nanoparticles with MPTS 22 2.2.2 Synthesis of PMMA-grafted ZrO2 nanoparticles 23 2.2.3 Preparation PMMA/ZrO2 hybrid nanocomposite 3D printing filaments 24 2.2.4 Preparation testing samples by Haake MiniJet machine 25 2.2.5 Preparation testing samples via fusion deposition modeling 3D printer 25 2.3 Characterization measurements 26 ii 2.3.1 Fourier-transform infrared spectroscopy 26 2.3.2 Tensile properties 26 2.3.3 Flexural properties 27 2.3.4 X-Ray diffraction spectra 27 2.3.5 Field Emission Scanning Electron Microscopy 27 2.3.6 Dynamic light scattering (DLS) 27 2.3.7 Thermal Gravimetric Analysis (TGA) 27 Chapter 3: RESULTS AND DISCUSSIONS 28 3.1 Characterization of ZrO2 nanoparticles modified with MPTS 28 3.1.1 Fourier-transform infrared spectroscopy 28 3.1.2 Thermal Gravimetric Analysis (TGA) 29 3.1.3 Field Emission Scanning Electron Microscopy and dynamic light scattering 30 3.1.4 The crystalline structures of samples 31 3.2 Synthesis and characterization of nanocomposites PMMA-g-ZrO2 from modified ZrO2 and MMA monomers 32 3.2.1 Fourier-transform infrared spectroscopy 32 3.2.2 Thermal Gravimetric Analysis (TGA) 33 3.2.3 XRD, DLS spectra and FESEM image 34 3.3 Fabrication and characterization of 3D printing filaments based on PMMA/ZrO2 hybrid nanocomposites 35 3.3.1 Evaluation of extrusion processing conditions 35 3.3.2 Characterization of 3D printing filaments based on PMMA/ZrO2 hybrid nanocomposite 38 3.3.3 Field Emission Scanning Electron Microscopy (FESEM image) 41 3.4 Characterization of 3D printed samples from PMMA/ZrO2 filaments 43 CONCLUSIONS AND RECOMMENDATIONS 46 LIST OF PUBLISHED PAPERS BY AUTHOR 47 REFERENCES 48 iii ABBREVIATIONS Abbreviations 3D Dimensions Definition 3DP 3-Dimensional printing AIBN α,α'-azobis(isobutyronitrile) DLS Dynamic light scattering DSC Differential scanning calorimetry DTG Derivative thermogravimetric FDM Fussion deposition modeling FESEM Field emission scanning electron microscope FTIR Fourier transform infrared gZrO2 PMMA grafted ZrO2 (PMMA-g- ZrO2) mZrO2 ZrO2 modified with MPTS MMA Methyl methacrylate MPTS 3-methoxypropyl trimethoxy silane oZrO2 Original ZrO2 (purchased from Aladdins company) PMMA Poly methyl methacrylate PMMA/ZrO2 PMMA/ZrO2 nanocomposites (using oZrO2, mZrO2, gZrO2) PMMA/gZrO2 PMMA/gZrO2 nanocomposite PMMA/mZrO2 PMMA/mZrO2 nanocomposite PMMA/oZrO2 PMMA/oZrO2 nanocomposite SEM Scanning electron microscope TGA Thermogravimetric analysis XRD X-Ray diffraction PMMA-g-ZrO2 PMMA grafted ZrO2 iv LIST OF FIGURES Figure 1.1: Schematic of the 3D printing technique Figure 1.2: (a): Types of 3D printing materials 3D printing; (b): Percentage of common polymers used for 3D printing in the world Figure 1.3: PMMA tacticities Figure 1.4: Scheme reaction ATRP 11 Figure 1.5: Baddeleyite mineral sample and its crystal structure 14 Figure 2.1: Modification procedure ZrO2 by MPTS 23 Figure 2.2: Synthesis of PMMA-grafted ZrO2 nanoparticles 23 Figure 2.3: Haake Rheomix 252p machine 24 Figure 2.4: (a): Haake MiniJet, (b): FDM 3D printer and testing samples 25 Figure 2.5: Fourier transform infrared spectroscopy (FT-IR), Nicolet iS10, Thermo Scientific – USA 26 Figure 2.6: Zwick Z2.5 universal mechanical testing machine (Germany) 26 Figure 2.7: Dynamic light scattering (DLS) instrument 27 Figure 3.1 FTIR spectra (a) oZrO2, (b) mZrO2 and (c) MPTS 28 Figure 3.2 Reaction scheme of (a): MPTS hydrolysis and (b): MPTS grafting onto ZrO2 nanoparticle 29 Figure 3.3 (a): TGA and (b) DTG curves of oZrO2 and mZrO2 nanoparticles 30 Figure 3.4: FESEM images of oZrO2 nanoparticles 30 Figure 3.5: FESEM images of mZrO2 nanoparticles 30 Figure 3.6: DLS diagrams of (a): oZrO2 and (b): mZrO2 nanoparticles 31 Figure 3.7: XRD patterns of (a): oZrO2 and (b): mZrO2 nanoparticles 31 Figure 3.8: FTIR spectra (a) oZrO2, (b) mZrO2 and (c) gZrO2 nanoparticles 33 Figure 3.9: Reaction scheme of the formation of PMMA-g-ZrO2 hybrid nanoparticle 33 Figure 3.10: TGA and DTG compared with oZrO2 and mZrO2 nanoparticles 34 Figure 3.11: (a) XRD spectrum and (b) FESEM image of gZrO2 nanoparticles 34 Figure 3.12: DLS curve of gZrO2 nanoparticles 35 Figure 3.13: PMMA and PMMA/ZrO2 3D printing filaments 36 v Figure 3.14: Flexural properties of PMMA/ZrO2 3D printing filaments with different contents of oZrO2, mZrO2, and gZrO2 39 Figure 3.15: Tensile properties of PMMA/ZrO2 3D printing filaments with different contents of ZrO2 41 Figure 3.16: FESEM image of PMMA/oZrO2 filaments wt.% 42 Figure 3.17: FESEM image of PMMA/mZrO2 filaments 5wt.% 43 Figure 3.18: FESEM image of PMMA/gZrO2 filaments 5wt.% 43 Figure 3.19: Printed specimen in bar (beam) shape prepared by using an FDM 3D printer from PMMA and PMMA/gZrO2 filaments 43 LIST OF TABLES Table 1.1: Several of 3D printing techniques [5] Table 1.2: Mechanical properties of zirconia [53] 15 Table 1.3: High temperature resistance and expansion [53] 15 Table 3.1: XRD analysis results of oZrO2 and mZrO2 nanoparticles 32 Table 3.2: PMMA/ZrO2 3D printing filaments fabricated at different conditions 36 Table 3.3: Processing ability evaluation 3D printing filaments 37 Table 3.4: Flexural properties of the 3D printing filaments of PMMA/mZrO2 hybrid nanocomposite (at mZrO2 content of 2.5wt.% at different processing conditions 38 Table 3.5: Flexural properties of PMMA/oZrO2 filaments 40 Table 3.6: Flexural properties of PMMA/mZrO2 filaments 40 Table 3.7: Flexural properties PMMA/gZrO2 filaments 40 Table 3.8: Tensile properties of PMMA ZrO2 filaments with different contents of ZrO2 (o, m, gZrO2) 41 Table 3.9: Tensile properties of 3D printing beams gZrO2 44 Table 3.10: Flexural properties of 3D printed beams gZrO2 44 INTRODUCTION Recently, three-dimensional (3D) printing technology is among the most attractive research fields for scientists The 3D printing technology allows to create more complex objects and products than tranditional manufacturing processes The 3D printing technologies are now being developed rapidly, bringing outstanding changes, and applied in the fields of aerospace, automobile manufacturing, mechanical construction, medical equipment, special jewelry, and even complex electronic circuit panels [1][2] Furthermore, 3D printing technologies can be applied in education fields such as STEM learning, skills development, and increased student and teacher engagement with the subject matter Polymer and polymer composite materials based on naturally derived polymers (gelatin, alginate, collagen, etc.) or synthetic polymers (polyethylene glycol (PEG), poly lactic-co-glycolic acid (PLGA), polyvinyl alcohol(PVA), etc) have been currently used for printing in the field of biomedical applications [3][4][5][6] Polymethyl methacrylate (PMMA), or plexiglass is a type of thermoplastic polymer, it belongs to the acrylic family resins PMMA is widely used in many industrial and life applications Specically, in the biomedical, PMMA is widely used as an important component of bone cements, and hard contact lenses [7] because of its biocompatibility with human and animal bodies Zirconia (ZrO 2) is also among the components of acrylic cements with the roles of reducing polymerization shrinkage, modifying mechanical properties and improving wear resistance, radiopacity and biological activity In the field of 3D printing materials, neat PMMA is less used alone in PMMA 3D printing materials Several studies have focused on studying polymer blends and composites from acrylic resins and expanding their applicability [8] [9] [10] Zirconia has been used as a reinforcement filler for many polymers as acrylic polymers, Acrylonitrile Butadiene Styrene (ABS), and epoxy resins However, it is an inorganic compound in nature, its surface energy differs from that of organic polymer matrix, leading to poorly compatible with organic polymers, and strongly reducing some properties of the polymer/zirconia systems [11] Therefore, several studies have focused on the enhancement of the interaction between zirconia and polymer by applying a physical or chemical surface modification of zirconia Most of studies aim to increase the dispersion of zirconia particles in the organic polymer matrix, or in other words changing the organic affinity of zirconia particles Many scientific works have been carried out published on the modification of zirconia by organic compounds, the most common of which is trialkoxysilane compound In addition, a new approach in surface treatment that is radical polymerization method in which modified nanoparticles was copolymerized with monomers, such as methyl methacrylate (MMA) [12] [13] Currently, there are few publications about using inorganic-organic hybrid materials such as PMMA-g-ZrO2 to reinforce in PMMA matrix and applied to 3D printing filaments Therefore, I performed a study entitled: “Fabrication and characterization of PMMA/ZrO2 hybrid nanocomposites towards the application in 3D printing filament materials” The aims of this master thesis are: (1) Successful modification of nanozirconia with using 3-mercaptopropyl-trimethoxysilane (labeled as mZrO2; (2): Successful synthesis of PMMA grafted zirconia nanoparticles (labeled as PMMA-g-ZrO2, or gZrO2); (3): Successful fabrication of 3D printing filaments based on PMMA and mZrO2 or gZrO2 by using a mini Haake extruder In additions, characterizations of mZrO2, gZrO2 nanoparticles and PMMA/ZrO2 nanocomposite filaments were performed and the obtained results were also discussed CHAPTER 1: OVERVIEW 1.1 Three-dimensional (3D) printing technology and 3D printing materials Three-dimensional (3D) printing technology is among the most attractive research fields for scientists in recent years The 3D printing technology can be used to create complex objects and products In 1984, Charles W Hull successfully invented a teacup on the first the stereolithography apparatus SLA1 by himself, and the related patent on stereolithography was issued on August 1984 He was also the co-founder of a 3D Printing Corporation (USA) After that, numerous related inventions by different methods, such that: (1) Selective sintering (SS) was developed by Carl R Deckard who worked at the University of Texas in 1986 Michael Feygin and colleague at Helisys, Inc was developed another method “forming integral objects from laminations” by using laminated manufacturing - LM in 1988 (2) Fused deposition modelling (FDM) was developed by Scott S Crump, at the company Stratasys, Inc in 1989 (3) Emanuel M Sachs and coworker, at Massachusetts Institute of Technology, develop “three-dimensional printing techniques”, a process of injecting binding agent and coloured ink on a bed of powdered material, using the injectors of a conventional ink-jet printer Currently, there are many 3D printing techniques (Table 1), the most popular ones are layered powder melting (PBF) including Selective laser sintering (SLS), selective laser melting (SLM), 3D inkjet printing (3D JP), photochemical embossing (SLG) [14][15][16][17], layered fusion printing (FFF/FDM) in Figure 1.1 Figure 1.1: Schematic of the 3D printing technique Three-dimensional (3D) printing technology is widely applied in the world such as automotive industry, construction, models designed, medical equipments, health care, etc [18] In the art field, this technology can create special objects and jewelry In the electronics industry, it is used to make 39 PMMA/gZrO2 and PMMA/mZrO2 filaments are about 0.7-3.6% and 0.3-1.8% higher than that of PMMA/oZrO2 filaments The remarkable results are that the flexural strength of PMMA/gZrO2 and PMMA/mZrO2 filament samples tend to increase compared to neat PMMA filament and reaches maximum value at 1wt.% ZrO2 content (3.6% higher than that of PMMA/oZrO2 wt.% filament), after that their flexural strength tends to decrease as shown in Figure 3.14b Figure 3.14: Flexural properties of PMMA/ZrO2 3D printing filaments with different contents of oZrO2, mZrO2, and gZrO2 Table 3.5, 3.6 and 3.7 represent the flexural properties including the flexural modulus of and the shrinkage (compared to the original length of the mold) of PMMA/oZrO2, PMMA/mZrO2 and PMMA/gZrO2 3D printing filaments, respectively Tables 3.5-3.7 show that the flexural modulus of all three kinds of PMMA/ZrO2 3D printing filaments increases with the ZrO2 content Meanwhile, the shrinkage of all PMMA/ZrO2 3D printing filaments tends to decrease with increasing ZrO2 content This result is also completely reasonable because ZrO2 is a good reinforcing agent for PMMA, especially at the nanoscale The thermal expansion of ZrO2 is also known as very low, additionally, it can also penetrate into the pores of PMMA matrix and reduce the overall shrinkage of PMMA/ZrO2 hybrid nanocomposite systems 40 Table 3.5: Flexural properties of PMMA/oZrO2 filaments Samples Flexural modulus (MPa) 7.56 Flexural strength (MPa) 110 Flexural strain (%) 2755 Shrinkage (%) PMMA/oZrO2 (1wt.%) 5.74 102.8 2765 1.41 PMMA/oZrO2 (2.5wt.%) 5.36 93.7 2789 1.37 PMMA/oZrO2 (5wt.%) 4.62 86.9 2818 1.33 PMMA/oZrO2 (7.5wt.%) 3.98 80.4 2869 1.14 PMMA 1.58 Table 3.6: Flexural properties of PMMA/mZrO2 filaments Samples Flexural modulus (MPa) 7.56 Flexural strength (MPa) 110 Flexural strain (%) 2755 Shrinkage (%) PMMA/mZrO2 (1wt.%) 7.08 105.5 2774 1.47 PMMA/mZrO2 (2.5wt.%) 6.35 98.6 2815 1.36 PMMA/mZrO2 (5wt.%) 5.10 96.4 2868 1.37 PMMA/mZrO2 (7.5wt.%) 4.41 91.0 2911 1.33 PMMA 1.58 Table 3.7: Flexural properties PMMA/gZrO2 filaments Samples Flexural modulus (MPa) 7.56 Flexural strength (MPa) 110 Flexural strain (%) 2755 Shrinkage (%) PMMA/gZrO2 (1wt.%) 7.26 114.4 2785 1.36 PMMA/gZrO2 (2.5wt.%) 6.76 113.1 2852 1.35 PMMA/gZrO2 (5wt.%) 6.15 101.2 2919 1.3 PMMA/gZrO2 (7.5wt.%) 4.81 96.7 2967 1.18 PMMA 1.58 As shown in Figure 3.15a, with increasing content of ZrO 2, the tensile strength of the PMMA/ZrO2 hybrid nanocomposites decreases It means the ZrO2 nanoparticles plays a important role as an inorganic dispersed phase which causes a decrease of the flexibility of PMMA matrix [74] Therefore, adding ZrO2 into PMMA matrix leads to decrease physico-mechanical properties of the PMMA 3D printing filaments Nevertheless, the tensile strength of the PMMA/gZrO2 filaments was higher (about than that of the PMMA/mZrO2 filaments and that of the PMMA/oZrO2 is the lowest, when 41 compared at the same ZrO2 content This indicates that the modification of ZrO2 nanoparticles is really necessary for the fabrication of the PMMA/ZrO2 hybrid nanocomposites as well as PMMA/ZrO2 filaments Figure 3.15: Tensile properties of PMMA/ZrO2 3D printing filaments with different contents of ZrO2 Table 3.8: Tensile properties of PMMA ZrO2 filaments with different contents of ZrO2 (o, m, gZrO2) oZrO2 PMMA/oZrO2 filaments 0wt.% wt.% 2.5 wt.% wt.% 7.5 wt.% E-moduls (MPa) 1546 ± 35 1556 ± 26 1563 ± 25 1573 ± 42 1583 ± 14 Elongation at break (%) 8.67 ± 0.5 6.82 ± 1.1 4.11 ± 0.7 3.85 ± 0.8 2.66 ± 0.2 Tensile strength (MPa) 72.3 ± 0.9 70.0 ± 1.6 65.9 ± 1.5 mZrO2 62.3 ± 0.8 60.5 ± 1.1 wt.% wt.% 2.5 wt.% wt.% 7.5 wt.% E-moduls (MPa) 1546 ± 26 1565 ± 20 1582 ± 30 1600 ± 25 1632 ± 20 Elongation at break (%) 8.67 ± 0.5 7.44 ± 0.2 6.45 ± 0.3 6.31 ± 0.4 5.63 ± 0.5 Tensile strength (MPa) 72.3 ± 0.9 71.55 ± 0.8 70.85 ± 1.2 70.48 ± 1.1 gZrO2 69.32 ± 0.9 PMMA/mZrO2 filaments PMMA/gZrO2 filaments wt.% wt.% 2.5 wt.% wt.% 7.5 wt.% E-moduls (MPa) 1546 ± 26 1566 ± 23 1569 ± 12 1593 ± 22 1636 ± 29 Elongation at break (%) 8.67 ± 0.4 8.67 ± 0.3 8.01 ± 0.3 7.45 ± 0.2 7.02 ± 0.3 Tensile strength (MPa) 72.3 ± 0.9 72.3 ± 0.8 72.9 ± 0.5 72.8 ± 0.6 71.82 0.4 Table 3.8 represents the tensile properties of ZrO2 materials (o, m, gZrO2) with different ZrO2 contents The results on tensile strength and elongation at break of ZrO2 have been represented and discussed above in Figure 3.15 Table 3.8 shows that the elastic modulus of 3D printing PMMA/ZrO2 hybrid filaments ranges from 1556 to 1636 MPa and tends to increase with ZrO2 42 content Among them, PMMA/gZrO2 filaments show the larger elastic modulus than PMMA/mZrO2 and PMMA/oZrO2 filaments On observation of the Young’s modulus of the PMMA/ZrO2 in Table 3.8, the obtained results indicates that the Young's modulus of the filament samples ranges from 1555 to 1635 MPa and tend to increase with the ZrO2 content Among them, gZrO2 nanoparticles can strongly increase the Young’s modulus of PMMA filament, next is for mZrO2 nanoparticles 3.3.3 Field Emission Scanning Electron Microscopy (FESEM image) Figure 3.16 represents the FESEM images of PMMA/oZrO2 (5 wt.%) at different magnifications Most of ZrO2 nanoparticles disperse well in the PMMA matrix at nanoscale from single particles to a cluster comprised from – nanoparticles with size from 10 to 200 nm Nevertheless, there are some large clusters, each cluster is comprised of several tens of nanoparticles with size of about - μm In overall, it can be seen that ZrO2 nanoparticles are well adhered with the PMMA matrix due to the good interaction polymer layer surrounding the ZrO2 nanoparticles Figures 3.17 and 3.18 show that when treated with MPTS silane or grafting with PMMA, the formation of clusters and amount of particles for each cluster in the PMMA/mZrO2 and PMMA/gZrO2 hybrid nanocomposites are reduced Each cluster comprised of to particles with size less than 200 nm This can be explained that the modification of ZrO2 with organic moieties (MPTS and PMMA) has reduced the surface energy of the ZrO2 nanoparticles, enhancing the organic affinity of the ZrO2 nanoparticles with the PMMA matrix As a result, the dispersion of mZrO2 and gZrO2 nanoparticles is better than that of oZrO2 nanoparticles Figure 3.16: FESEM image of PMMA/oZrO2 filaments wt.% 43 Figure 3.17: FESEM image of PMMA/mZrO2 filaments 5wt.% Figure 3.18: FESEM image of PMMA/gZrO2 filaments 5wt.% 3.4 Characterization of 3D printed samples from PMMA/ZrO2 filaments The testing samples from PMMA/gZrO2 2.5 wt.% is shown in Figure 3.19 The image shows a clear opalescent color due to both the air pore and the radiopacity of ZrO2 Figure 3.19: Printed specimen in bar (beam) shape prepared by using an FDM 3D printer from PMMA and PMMA/gZrO2 filaments Table 3.9 is the tensile properties of 3D printed beams made by using the FDM 3D printer from PMMA/ZrO2 hybrid nanocomposite filaments, in this case, the tensile test standard is performed according to ASTM D866 applied to bar/beam shapes The labels of ΔσT, ΔE and ΔɛT are corresponding to the decrements in tensile strength, elastic modulus and elongation at break of printed samples and molded samples prepared from the same kind of filaments The results show that the tensile strength of the printed samples is quite high, from 38.5 to 43.9 MPa, the elastic modulus is varied from 1119 to 1405 MPa 44 and the elongation at break is varied from 4.06 to 26 (%) It can also be seen that all tensile strength measurements of the 3D printed samples are smaller than those of the corresponding molded samples The decrement of Δσ is ranged from 40 to 47 %, the largest is for PMMA and smaller is for samples containing gZrO2 The decrement of ΔBM is ranged from 3.9 to 4.8 %, the largest is for PMMA and smaller is for samples containing gZrO2 (39 – 43 %) Table 3.9: Tensile properties of 3D printing beams gZrO2 σT (MPa) ΔσT (%) E (MPa) ΔE (%) ɛT (%) ΔɛT (%) PMMA 38.5 47 ↓ 1119 28 ↓ 5.26 39 ↓ PMMA/gZrO2 (1wt.%) 42.8 41 ↓ 1275 19 ↓ 4.56 43 ↓ PMMA/gZrO2 (2.5wt.%) 43.9 40 ↓ 1372 14 ↓ 4.41 41 ↓ PMMA/gZrO2 (7.5wt.%) 43.1 40 ↓ 1405 14 ↓ 4.06 42 ↓ Printed samples Note: E – Elastic moduls, σT – tensile strength, ɛT – elongation at break; ΔE, ΔσT, ΔɛT are correspondingly the reductions of E, σT and ɛT Table 3.10: Flexural properties of 3D printed beams gZrO2 Printed samples Flexural ΔσB Flexural ΔBM Flexural ΔɛB strength (%) moduls (%) strain (%) (MPa) (MPa) (%) PMMA 103 10.0 ↓ 2652 4.8 ↓ 4.5 38 ↓ PMMA/gZrO2 (1wt.%) 102 9.8 ↓ 2722 4.6 ↓ 3.81 44 ↓ PMMA/gZrO2 (2.5wt.%) 95 6.1 ↓ 2793 4.3 ↓ 3.55 42 ↓ PMMA/gZrO2 (7.5wt.%) 92 4.9 ↓ 2852 3.9 ↓ 2.85 41 ↓ Table 3.10 is the flexural properties of 3D printed beam samples fabricated by the FDM 3D printing method from the 3D printing filaments based on PMMA/ZrO2 hybrid nanocomposites The values Δσ, ΔBM and Δɛ are the decrements in flexural strength, flexural modulus and flexural strain between printed samples and molded samples It should be noted that the flexural properties of molded samples have been discussed in aforementioned sections The results in Table 3.10 show that the flexural strength of the 3D printed beams is still quite high (92 – 103 MPa), the flexural modulus of the 3D printed samples is varied from 2652 to 2852 MPa and the flexural strain is varied from 2.85 to 4.5 (%) It can also be seen that all flexural measurements of the 3D printed samples are smaller than that of the corresponding molded samples 45 prepared from the same 3D printing filaments The decrease in Δσ is varied in the range of 4.9 - 10 %, the largest is for PMMA and smaller is for the filaments samples containing gZrO2 The decrease in ΔBM is ranged from 3.9 to 4.8 %, the largest is for PMMA and the smaller is for the samples containing gZrO2, the decrement ΔBM is varied in the range of 38 – 44 % In this study, the PMMA/ZrO2 is view as a biomaterial, which can be used for making a prosthetic implant, or a defected bone In this case, 3D printing technology show advantages for making a suitable implant for certain patient Like bone cements, the samples are recommended under testing with ISO 5833:2002 standard, in which the required flexural strength and modulus of PMMA acrylic bone cements are 50 MPa and 1800 MPa, respectively Table 3.10 reveals that the flexural strength and flexural modulus of the 3D-printed testing samples are much higher than those of the required values in the ISO 5833:2002 standard This suggests that 3D printing technology can be applied for making acrylic resin implants 46 CONCLUSIONS AND RECOMMENDATIONS CONCLUTIONS - MPTS-modified nanoparticles (mZrO2) have been synthesized by using silanization method at pH 8.5 and room temperature for 24 h DLS indicated the nanodistribution of mZrO2 with average size of 155.5 nm with relatively low polydispersity index (0.283) FTIR and TGA indicated that the MPTS was grafted onto the surface of the ZrO2 with the grafting percentage of 2.5 wt.% - PMMA-grafted ZrO2 nanoparticles (gZrO2) have been synthesized via copolymerization between MMA and mZrO2 at 60°C for h, the grafting percentage of PMMA onto the surface of the ZrO2 was evalueted as 9.03 wt.% by TGA The DLS patterns showed that the polydispersity index and particle size distribution of gZrO2 nanoparticles were higher compared with mZrO2 nanoparticles FESEM images and XRD patterns indicated primary ZrO2 nanoparticles did not change after silanization and PMMA grafting - The 3D printing PMMA/ZrO2 nanocomposite filaments have been fabricated via melt extrusion process using origin ZrO2 (oZrO2), mZrO2 and gZrO2 as fillers with contents from to 7.5wt.% at temperature profile of 190200-210-210 °C and rotor speed of 80 rpm The flexural strength and modulus as well as tensile strength and modulus of PMMA/mZrO2 and PMMA/gZrO2 filamments were higher than those of PMMA/oZrO2 filamments FESEM studies showed that oZrO2, mZrO2 and gZrO2 nanoparticles dispersed well in the PMMA matrix in nanoscale despite of some micron size clusters - The printed samples from the PMMA/ZrO2 nanocomposite filaments still exhibited relative high values of tensile and flexural properties The flexural strength and modulus of printed samples were varied in the ranged of 92-102 MPa and 2722 – 2852 MPa, respectively The PMMA/ZrO2 hybrid nanocomposite filaments can be applied to prepare acrylic prosthetic implants with relative high mechanical properties RECOMMENDATIONS - Improvement of the fabrication of the PMMA/ZrO2 3D printing filaments in large scale for commercial purpose; - Evaluation of cytotoxicity of the PMMA/ZrO2 3D printing filaments should be further investigated 47 LIST OF PUBLISHED PAPERS BY AUTHOR Nguyen Thi Dieu Linh, Do Quang Tham, Nguyen Vu Giang, Tran Huu Trung, Le Thi My Hanh, Nguyen Thi Thu Trang, Nguyen Thuy Chinh, Tran Thi Mai, Thai Hoang and Do Van Sy “Synthesis and characterization of monodisperse hydrous colloidal zirconia nanoparticles” Communications in Physics, Vol 30, No (2020), pp 391-398 Nguyen Thi Dieu Linh, Nguyen Thi Kim Dung, Do Quang Tham, Dam Xuan Thang The Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles Vietnam Journal of Science and Technology, 2022 (Accepted) 48 REFERENCES Pandey M., Choudhury H., Fern J L C., Kee A T K., Kou J., Jing J L J., Her H C., Yong H S., Ming H C., Bhattamisra S K., Gorain B., 2020, 3D printing for oral drug delivery: a new tool to customize drug delivery, Drug Delivery and Translational Research, 10(4), 986-1001 Cui M., Pan H., Su Y., Fang D., Qiao S., Ding P., Pan W., 2021, Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development, Acta Pharmaceutica Sinica B, 11(8), 2488-2504 Chen J., Zhang Z., Chen X., Zhang C., Zhang G., Xu Z., 2014, Design and manufacture of customized dental implants by using reverse engineering and selective laser melting technology, The Journal of Prosthetic Dentistry, 112(5), 1088-1095 Oliveira T T., Reis A C., 2019, Fabrication of dental implants by the additive manufacturing method: A systematic review, The Journal of Prosthetic Dentistry, 122(3), 270-274 Gao C., Wang C., Jin H., Wang Z., Li Z., Shi C., Leng Y., Yang F., Liu H., Wang J., 2018, Additive manufacturing technique-designed metallic porous implants for clinical application in orthopedics, RSC Advances, 8(44), 25210-25227 Chen R K., Jin Y.-a., Wensman J., Shih A., 2016, Additive manufacturing of custom orthoses and prostheses—A review, Additive Manufacturing, 12, 77-89 Esmi A., Jahani Y., Yousefi A A., Zandi M., 2019, PMMA-CNT-HAp nanocomposites optimized for 3D-printing applications, Materials Research Express, 6(8), 085405 Stansbury J W., Idacavage M J., 2016, 3D printing with polymers: Challenges among expanding options and opportunities, Dental Materials, 32(1), 54-64 Mendes-Felipe C., Oliveira J., Etxebarria I., Vilas-Vilela J L., LancerosMendez S., 2019, State-of-the-Art and Future Challenges of UV Curable Polymer-Based Smart Materials for Printing Technologies, Advanced Materials Technologies, 4(3), 1800618 10 Wagner A., Kreuzer A M., Göpperl L., Schranzhofer L., Paulik C., 2019, Foamable acrylic based ink for the production of light weight parts by inkjet-based 3D printing, European Polymer Journal, 115, 325-334 11 Gad M M., Abualsaud R., Rahoma A., Al-Thobity A M., Al-Abidi K S., Akhtar S., 2018, Effect of zirconium oxide nanoparticles addition on the optical and tensile properties of polymethyl methacrylate denture base material, International Journal of Nanomedicine, 13, 283-292 12 Hu Y., Gu G., Zhou S., Wu L., 2011, Preparation and properties of transparent PMMA/ZrO2 nanocomposites using 2-hydroxyethyl methacrylate as a coupling agent, Polymer, 52(1), 122-129 49 13 Reyes-Acosta M A., Torres-Huerta A M., Domínguez-Crespo M A., Flores-Vela A I., Dorantes-Rosales H J., Ramírez-Meneses E., 2015, Influence of ZrO2 nanoparticles and thermal treatment on the properties of PMMA/ZrO2 hybrid coatings, Journal of Alloys and Compounds, 643, S150-S158 14 Rayna T., Striukova L., 2016, From rapid prototyping to home fabrication: How 3D printing is changing business model innovation, Technological Forecasting and Social Change, 102, 214-224 15 Jasveer S., Jianbin X., 2018, Comparison of Different Types of 3D Printing Technologies, International Journal of Scientific and Research Publications, 8(4), 1-9 16 Berman B., 2012, 3-D printing: The new industrial revolution, Business horizons, 55(2), 155-162 17 Attaran M., 2017, The rise of 3-D printing: The advantages of additive manufacturing over traditional manufacturing, Business horizons, 60(5), 677-688 18 Mạnh Quân N., 2017, In 3D-Công nghệ đỉnh cao phát triển, Tạp chí Khoa học Công nghệ Việt Nam, 10, 37-40 19 Moreau C., Zeijderveld J V., 2018, State of 3D Printing 2018: The rise of metal 3D printing, DMLS, and finishes, Sculpteo’s 4th annual report on 3D Printing and Digital Manufacturing 20 Statista, 2018, Worldwide most used 3D printing materials, as of July 2018, https://www.statista.com/statistics/800454/worldwide-most-used3d-printing-materials/, Statista GmbH, Johannes-Brahms-Platz 1, 20355 Hamburg, Germany 21 Parandoush P., Lin D., 2017, A review on additive manufacturing of polymer-fiber composites, Composite Structures, 182, 36-53 22 Ngo T D., Kashani A., Imbalzano G., Nguyen K T Q., Hui D., 2018, Additive manufacturing (3D printing): A review of materials, methods, applications and challenges, Composites Part B: Engineering, 143, 172196 23 Wittbrodt B., Pearce J M., 2015, The effects of PLA color on material properties of 3-D printed components, Additive Manufacturing, 8, 110116 24 Wang X., Jiang M., Zhou Z., Gou J., Hui D., 2017, 3D printing of polymer matrix composites: A review and prospective, Composites Part B: Engineering, 110, 442-458 25 Nematollahi M., Jahadakbar A., Mahtabi M J., Elahinia M., 2019, in M Niinomi, Metals for Biomedical Devices (Second Edition), Woodhead Publishing, 331-353 26 Duda T., Raghavan L V., 2016, 3D Metal Printing Technology, IFACPapersOnLine, 49(29), 103-110 27 Ronca A., Maiullari F., Milan M., Pace V., Gloria A., Rizzi R., De Santis R., Ambrosio L., 2017, Surface functionalization of acrylic based 50 28 29 30 31 32 33 34 35 36 37 38 photocrosslinkable resin for 3D printing applications, Bioactive Materials, 2(3), 131-137 Dung H T., 2018, Fabrication and characterization of supercapacitor electrode by 3D printing, Vietnam Journal of Science and Technology, 56(5), 574-581 Palanisamy P., Chavali M., Kumar E M., Etika K C., 2020, Chapter 10 Hybrid nanocomposites and their potential applications in the field of nanosensors/gas and biosensors, in K Pal and F Gomes, Nanofabrication for Smart Nanosensor Applications, Elsevier, 253-280 Roy S., Singha N R., 2017, Polymeric Nanocomposite Membranes for Next Generation Pervaporation Process: Strategies, Challenges and Future Prospects, Membranes, 7(3), 53 de Oliveira A D., Beatrice C A G., 2018, in S Subbarayan, Nanocomposites-Recent Evolutions, InTechOpen, London, 103-127 Naz A., Kausar A., Siddiq M., Choudhary M A., 2016, Comparative Review on Structure, Properties, Fabrication Techniques, and Relevance of Polymer Nanocomposites Reinforced with Carbon Nanotube and Graphite Fillers, Polymer-Plastics Technology and Engineering, 55(2), 171-198 Tavares M I B., da Silva E O., da Silva P R., de Menezes L R., 2017, in M.S Seehra, Nanostructured Materials: Fabrication to Applications, IntechOpen, London, 135-151 Canetti M., Scafati S T., Cacciamani A., Bertini F., 2012, Influence of hydrogenated oligo(cyclopentadiene) on the structure and the thermal degradation of polypropylene-based nanocomposites, Polymer Degradation and Stability, 97(1), 81-87 Rousseaux D D J., Sallem-Idrissi N., Baudouin A.-C., Devaux J., Godard P., Marchand-Brynaert J., Sclavons M., 2011, Water-assisted extrusion of polypropylene/clay nanocomposites: A comprehensive study, Polymer, 52(2), 443-451 Wang B., Wilkes G L., 1991 New Ti-PTMO and Zr-PTMO ceramer hybrid materials prepared by the sol gel method: Synthesis and characterization, Journal of Polymer Science Part A: Polymer Chemistry, 29(6), 905-909 Tavares M R., de Menezes L R., Nascimento D F., Souza D H S., Reynaud F., Marques M F V., Tavares M I B., 2016, Polymeric nanoparticles assembled with microfluidics for drug delivery across the blood-brain barrier, The European Physical Journal Special Topics, 225(4), 779-795 Valentim A C S., Tavares M I., da Silva E O., 2013, The effect of the Nb2O5 dispersion on ethylene vinyl acetate to obtain ethylene vinyl acetate/Nb2O5 nanostructured materials, Journal of Nanoscience and Nanotechnology, 13(6), 4427-32 51 39 Xi G X., Song S L., Liu Q., 2005, Catalytic effects of sulfates on thermal degradation of waste poly(methyl methacrylate), Thermochimica Acta, 435(1), 64-67 40 Harper C A., Petrie E M., 2004, Plastics materials and processes - a concise encyclopedia - Book Review, IEEE Electrical Insulation Magazine, 20(4), 47-48 41 Van Krevelen D W., Te Nijenhuis K., 2009, Properties of polymers: their correlation with chemical structure; their numerical estimation and prediction from additive group contributions, UK, Elsevier, London 42 Grelle P F (2006), Handbook of Plastic Processes, John Wiley & Sons, Canada, 1-123 43 Park J H., Hwang D K., Lee J., Im S., Kim E., 2007, Studies on poly(methyl methacrylate) dielectric layer for field effect transistor: Influence of polymer tacticity, Thin Solid Films, 515(7), 4041-4044 44 Soleymani Eil Bakhtiari S., Bakhsheshi-Rad H R., Karbasi S., Tavakoli M., Hassanzadeh Tabrizi S A., Ismail A F., Seifalian A., RamaKrishna S., Berto F., 2021, Poly(methyl methacrylate) bone cement, its rise, growth, downfall and future, Polymer International, 70(9), 1182-1201 45 Geng K., Tsui O., 2016, Effects of Polymer Tacticity and Molecular Weight on the Glass Transition Temperature of Poly(methyl methacrylate) Films on Silica, Macromolecules, 49 46 Bhat G., Kandagor V., 2014, in D Zhang, Advances in Filament Yarn Spinning of Textiles and Polymers, Woodhead Publishing, 3-30 47 Vernieuwe K., Lommens P., Martins J C., Van Den Broeck F., Van Driessche I., De Buysser K., 2013, Aqueous ZrO₂ and YSZ Colloidal Systems through Microwave Assisted Hydrothermal Synthesis, Materials (Basel, Switzerland), 6(9), 4082-4095 48 Bao L., Li X., Wang Z., Li J., 2018, Fabrication and characterazation of functionalized zirconia microparticles and zirconia-containing bone cement, Materials Research Express, 5(7), 075404 49 Duan G., Zhang C., Li A., Yang X., Lu L., Wang X., 2008, Preparation and characterization of mesoporous zirconia made by using a poly (methyl methacrylate) template, Nanoscale research letters, 3(3), 118 50 Liu Z., Tang Y., Kang T., Rao M., Li K., Wang Q., Quan C., Zhang C., Jiang Q., Shen H., 2015, Synergistic effect of HA and BMP-2 mimicking peptide on the bioactivity of HA/PMMA bone cement, Colloids and Surfaces B: Biointerfaces, 131, 39-46 51 Arturo S., Comprehensive Guide on Polymethyl methacrylate (PMMA or Acrylic), 2022; Accessed on 25 Aug 2022, https://omnexus.specialchem.com/selection-guide/polymethylmethacrylate-pmma-acrylic-plastic 52 Sabu T., Preetha B., Sreekala M S., 2018, in K Shanmugam and R Sahadevan, Fundamental biomaterials: ceramics, Elsevier, UK, 1-46 52 53 911Metallurgist, Making Zirconia by Zirconium Chlorination, 2021; 25 Aug 2022, https://www.911metallurgist.com/making-zirconia/ 54 Fedorov P P., Yarotskaya E G., 2021, Zirconium dioxide Review, Condensed Matter and Interphases, 23(2), 169-187 55 El-Barawy K A., Morsi I M., El-Tawil S Z., Francis A A., Chlorination of zirconium bearing materials to produce high purity zirconia, in AIME 126 Th., SME Annual Meeting and Exhibit 1997: Denver, Colorado-USA 56 Nature News, 1917, The Use of Zirconia as a Refractory Material, Nature, 99(2488), 375-376 57 Domingo-Roca R., Jackson J C., Windmill J F C., 2018, 3D-printing polymer-based permanent magnets, Materials & Design, 153, 120-128 58 Malik H H., Darwood A R J., Shaunak S., Kulatilake P., El-Hilly A A., Mulki O., Baskaradas A., 2015, Three-dimensional printing in surgery: a review of current surgical applications, Journal of Surgical Research 59 Polzin C., Spath S., Seitz H., 2013, Characterization and evaluation of a PMMA-based 3D printing process, Rapid Prototyping Journal, 19(1), 3743 60 Dung H T., Dung T Q., Huy N T., Yến N T., 2017, Building a 3D printer for rapid prototyping using plastic materials, Tạp chí Khoa học Cơng nghệ Đại học Công nghiệp Hà Nội, 39(4), 72-77 61 Tung D T., Dung H T., 2019, Study on fast charger for 5V 1500F supercapacitor module from photovoltaic panel, Vietnam Journal of Science and Technology, 57(1), 82-91 62 Tam L T T., Hung N V., Tung D T., Dung N T., Dung H T., Dung N T., Minh P N., Hong P N., Lu L T., 2019, Synthesis and electrochemical properties of porous CNTs-ferrite hybrid nanostructures for supercapacitor, Vietnam Journal of Science and Technology, 57(1), 58-66 63 Lan P X., Lee J W., Seol Y.-J., Cho D.-W., 2009, Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification, Journal of Materials Science: Materials in Medicine, 20(1), 271-279 64 Park H.-S., Dang X.-P., 2017, Development of a Smart Plastic Injection Mold with Conformal Cooling Channels, Procedia Manufacturing, 10, 4859 65 Tran N.-H., Nguyen V.-N., Ngo A.-V., Nguyen V.-C., 2017, Study on the Effect of Fused Deposition Modeling (FDM) Process Parameters on the Printed Part Quality, Int Journal of Engineering Research and Application, 7(12), 71-77 66 Intellectual property office of Vietnam, wopublish-search "in 3D", 2022; 27 Aug 2022, http://wipopublish.ipvietnam.gov.vn/wopublishsearch/public/patents?9&query=*:* 67 Yang J., Liao M., Hong G., Dai S., Shen J., Xie H., Chen C., 2020, Effect of APTES- or MPTS-Conditioned Nanozirconia Fillers on Mechanical 53 68 69 70 71 72 73 74 Properties of Bis-GMA-Based Resin Composites, ACS Omega, 5(50), 32540-32550 Dick A., Bhandari B., Prakash S., 2019, 3D printing of meat, Meat Science, 153, 35-44 Li D., Yao J., Liu B., Sun H., van Agtmaal S., Feng C., 2019, Preparation and characterization of surface grafting polymer of ZrO2 membrane and ZrO2 powder, Applied Surface Science, 471, 394-402 Tham D Q., Huynh M D., Linh N T D., Van D T C., Cong D V., Dung N T K., Trang N T T., Lam P V., Hoang T., Lam T D., 2021, PMMA Bone Cements Modified with Silane-Treated and PMMA-Grafted Hydroxyapatite Nanocrystals: Preparation and Characterization, Polymers, 13(22), 3860 Johnson C S., Gabriel D A., 2018, in B.J E., Spectroscopy in Biochemistry, CRC Press, 177-248 Song Y L., 2020, Trends in prosthodontics of dental implantology, Chinese journal of stomatology, 55(11), 809-813 Yao T., Deng Z., Zhang K., Li S., 2019, A method to predict the ultimate tensile strength of 3D printing polylactic acid (PLA) materials with different printing orientations, Composites Part B: Engineering, 163, 393402 McMurdie H F., Morris M C., Evans E H., Paretzkin B., Wong-Ng W., Ettlinger L., Hubbard C R., 2013, Standard X-Ray Diffraction Powder Patterns from the JCPDS Research Associateship, Powder Diffraction, 1(2), 64-77